Nice find on those door glass blocks. I have a couple of 73-75 a-bodys and I was lucky enough to find some blocks for those cars on eBay a while back.
As for the grounding of the actuators, I do know that the passenger side actuator did not have to be grounded to the door to work, because after our discussion here, I checked for that. I tested it in my hand, free from the door, and it worked without being grounded to the door.
When I did the driver side door earlier, I just assumed the actuator bracket needed to be grounded, so I was doing my testing of my spare actuators by grounding them against the door. From what I remember, I didn't think they worked when I didn't rub the bracket against the driver door metal hard enough to get a good ground. So, that's why I was thinking they needed grounding. If I'd known that there would be doubt about whether the driver side actuator needs to ground on the door, I would have paid more attention at that time. At this point, I am wondering if maybe the driver's side actuator must be grounded to pass the ground over to the passenger side. But, after looking at the wiring diagram in my 79 Fisher Body manual, a ground wire appears to come off of the driver side pdl switch and would be screwed to the door somewhere. So, if the switch is wired like in the book, it wouldn't seem necessary to ground the actuator.
As for the rivets, if you ever removed them, and wanted to replace them with rivets, you know that you can still get new ones at a body and paint supply store or other place where auto fasteners are sold.